Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
  • C07C209/68—Preparation of compounds containing amino groups bound to a carbon skeleton from amines, by reactions not involving amino groups, e.g. reduction of unsaturated amines, aromatisation, or substitution of the carbon skeleton
  • C07C209/74—Preparation of compounds containing amino groups bound to a carbon skeleton from amines, by reactions not involving amino groups, e.g. reduction of unsaturated amines, aromatisation, or substitution of the carbon skeleton by halogenation, hydrohalogenation, dehalogenation, or dehydrohalogenation
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N33/00—Biocides, pest repellants or attractants, or plant growth regulators containing organic nitrogen compounds
  • A01N33/02—Amines; Quaternary ammonium compounds
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C211/00—Compounds containing amino groups bound to a carbon skeleton
  • C07C211/43—Compounds containing amino groups bound to a carbon skeleton having amino groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton
  • C07C211/44—Compounds containing amino groups bound to a carbon skeleton having amino groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton having amino groups bound to only one six-membered aromatic ring
  • C07C211/45—Monoamines
  • C07C211/46—Aniline

Definitions

• the present invention relates to a novel process for the preparation of a 2,6-dihalo-para-trifluoromethylaniline from para-trifluoromethylaniline.
• Patent Application WO 00/35851 discloses a process for the preparation of a 2,6-dihalo-para-trifluoromethylaniline from a trihalo-para-trifluoromethylbenzene at a temperature of between 130 and 350° C. in a preferably polar solvent.
• the use of para-trifluoromethylaniline for the preparation of 2,6-dihalo-para-trifluoromethylaniline does not appear in this patent application.
• Patent Applications FR 2 810 665 and WO 01/64623 disclose a process for the preparation of 2,6-dichloro-para-trifluoromethylaniline by chlorination of precursor anilines in a hydrofluoric acid medium.
• the precursor compound is trifluoromethylphenylcarbamoyl fluoride.
• the use of an other solvent than hydrofluoric acid is not mentioned.
• a subject-matter of the present invention is thus a process for the preparation of a compound of general formula (I):
• X represents a halogen atom.
• X can be a chlorine atom, a bromine atom, an iodine atom or a fluorine atom.
• the compound of general formula (I) preferably prepared by virtue of the process according to the present invention is 2,6-dichloro-para-trifluoromethylaniline, which is particularly useful in the synthesis of fipronil, an insecticidal compound of phenylpyrazole type.
• the solvent used during the preparation of the compound of general formula (I) according to the present invention is a polar aprotic solvent.
• a preferred polar aprotic solvent can be a chlorinated aromatic solvent, such as monochlorobenzene, or a chlorinated aliphatic solvent, such as dichloroethane. In an entirely preferred way, monochlorobenzene will be chosen as solvent.
• the dihalogen/compound (II) molar ratio is chosen as ranging from 1.9 to 2.5 during the preparation of the 2,6-dihalo-para-trifluoromethylaniline according to the present invention.
• the dihalogen/compound (II) molar ratio is preferably chosen as ranging from 2 to 2.05.
• the temperature of the reaction medium according to the present invention is chosen as ranging from 100 to 300° C.
• the temperature of the reaction medium is preferably chosen as ranging from 100 to 130° C. In an entirely preferred way, the temperature of the reaction medium is chosen as ranging from 105° C. to 115° C.
• the process according to the present invention consists in preparing 2,6-dichloro-para-trifluoromethylaniline by simultaneously introducing para-trifluoromethylaniline and Cl 2 into monochlorobenzene in a Cl 2 /para-trifluoromethylaniline molar ratio of between 1.85 and 2.05, at a temperature ranging from 105 to 115° C.
• the process according to the present invention can be carried out according to general techniques known to a person skilled in the art.
• the process according to the present invention can be carried out in a jacketed reactor equipped with a stirring device and surmounted by a reflux condenser maintained at a temperature of less than or equal to ⁇ 10° C.
• the halogen necessary for the reaction will be introduced via a dip pipe arriving with stirring.
• the stirrer preferably used will make it possible to provide optimum micromixing of the reactants. This can be carried out by a stirrer of impeller type or by any other stirrer well known to a person skilled in the art.
• hydrochloric acid in the gaseous form is produced.
• the latter is subsequently generally absorbed by a sodium hydroxide trap.
• para-trifluoromethylaniline reacts instantaneously on contact with hydrochloric acid to form para-trifluoromethylaniline hydrochloride, para-trifluoromethylaniline will preferably be fed to the reactor via a dip pipe, in order to avoid blockages.
• the product obtained by virtue of the process according to the present invention (2,6-dihalo-para-trifluoromethylaniline) has a sufficient degree of purity to be reused directly in the synthesis of the pesticidal compounds of phenylpyrazole type. It is generally considered that the degree of purity should be at least 96% in order for the product to be able to be used in the continuation of a preparation process.
• the 2,6-dihalo-para-trifluoromethylaniline obtained can also be isolated, in particular in order to be stored, by distillation of the solvent according to techniques known to a person skilled in the art.
• the reactor is subsequently fed with a 70% solution of para-trifluoromethylaniline in monochlorobenzene at a flow rate of 792 kg/h for 6 h 30 and with Cl 2 at a flow rate of 488 kg/h.
• the temperature is maintained at 110° C. by cooling the jacket.
• the monochlorobenzene is distilled off by placing the reactor under gradually increasing vacuum through a distillation column. After removal of the solvent, the 2,6-dichloro-para-trifluoromethylaniline is cooled to 60° C. before emptying the reactor to the storage tank.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Pest Control & Pesticides (AREA)
• Plant Pathology (AREA)
• Health & Medical Sciences (AREA)
• Agronomy & Crop Science (AREA)
• Dentistry (AREA)
• General Health & Medical Sciences (AREA)
• Wood Science & Technology (AREA)
• Zoology (AREA)
• Environmental Sciences (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)

Applications Claiming Priority (3)

Publications (2)

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Country Status (23)

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Citations (5)

• 2002
  • 2002-10-25 FR FR0213392A patent/FR2846325B1/fr not_active Expired - Lifetime
• 2003
  • 2003-10-24 WO PCT/EP2003/013340 patent/WO2004037766A2/en active Application Filing
  • 2003-10-24 CN CNB2003801019166A patent/CN100519510C/zh not_active Expired - Lifetime
  • 2003-10-24 UA UAA200504880A patent/UA79998C2/uk unknown
  • 2003-10-24 ES ES03780071T patent/ES2316840T3/es not_active Expired - Lifetime
  • 2003-10-24 JP JP2004546031A patent/JP4511359B2/ja not_active Expired - Fee Related
  • 2003-10-24 AU AU2003288184A patent/AU2003288184B2/en not_active Expired
  • 2003-10-24 SI SI200331493T patent/SI1558560T1/sl unknown
  • 2003-10-24 KR KR1020057006958A patent/KR20050055780A/ko not_active Application Discontinuation
  • 2003-10-24 DE DE60325631T patent/DE60325631D1/de not_active Expired - Lifetime
  • 2003-10-24 EA EA200500688A patent/EA008062B1/ru not_active IP Right Cessation
  • 2003-10-24 BR BRPI0315671-0A patent/BR0315671B1/pt active IP Right Grant
  • 2003-10-24 DK DK03780071T patent/DK1558560T3/da active
  • 2003-10-24 AT AT03780071T patent/ATE419230T1/de active
  • 2003-10-24 EP EP03780071A patent/EP1558560B1/en not_active Expired - Lifetime
  • 2003-10-24 CA CA002503188A patent/CA2503188A1/en not_active Abandoned
  • 2003-10-24 MX MXPA05004234A patent/MXPA05004234A/es active IP Right Grant
  • 2003-10-24 PL PL375378A patent/PL207084B1/pl not_active IP Right Cessation
  • 2003-10-24 TW TW092129612A patent/TWI295154B/zh not_active IP Right Cessation
  • 2003-10-24 US US10/532,160 patent/US7553993B2/en not_active Expired - Lifetime
  • 2003-10-24 PT PT03780071T patent/PT1558560E/pt unknown
• 2005
  • 2005-04-18 IL IL168096A patent/IL168096A/en active IP Right Grant
  • 2005-05-24 ZA ZA200504203A patent/ZA200504203B/en unknown

Patent Citations (8)

Non-Patent Citations (2)

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